Mechanical abrasion resistant candle soot based superhydrophobic coating over nanosecond laser textured stainless steel

In this report, we show that using naturally hydrophobic wax bound carbon soot nanoparticles (WCN) as fillers over laser ablation textured stainless steel surface, a mechanical abrasion resistant superhydrophobic (SH) surface can be prepared. The abrasion resistance may be due to the fact that during mechanical abrasions, the WCN lying in the lower layers of the laser textured surface get spread over the abraded surfaces and maintain superhydrophobicity. Further, the laser created grooves provide a space for the WCN to stay protected from abrasions so that all the WCN do not get wiped away at once. The developed SH surface when abraded by a sandpaper of 3000 grit loaded with 8 kPa load was found to exhibit similar to 157 degrees contact angle and similar to 7 degrees sliding angle even after 40 cycles of abrasions which corresponded to similar to 400 mm abrasion distance. Further, the SH surface obtained by using WCN over laser textured surface was also found to have better abrasion resistance when compared with the SH surface prepared via the conventional fluorosilane coating over laser textured surface.